Saturday, 7 July 2012

Raspberry Pi PS2 - Part 1

After not being imaginative enough to think of anything useful to do
with my Raspberry Pi, I decided to put it in a case with a few other
bits to make a semi-useful mini PC. The target? Slimline PS2 I got off eBay for 7 quid (faulty laser). I've always liked the slim PS2 case. I'd have bought a brand new housing kit instead, but I couldn't find one in black. DX were (and still are) out of stock (item 29213). Anyway, it was a bit scuffed but would do the job.

I wanted rid of the disgusting sticker on the back, but as it turns out, Sony do a better job of making stickers than they do lasers. It wouldn't peel off.

The trick seems to be a syringe of isopropanol and careful scraping with something softer than the PS2 plastics - I used an iTunes giftcard.

The isopropanol didn't instantly dissolve the glue like it does with other stuff, so who knows, maybe water or soap or something would have worked instead. Who cares.

The finished result I was happy with though, no nasty sticky marks left at all.

Opening it up, I was quite surprised that the entire innards come out in one chunk. There's a screw tucked away between the controller ports that's easily missed *ahem*.

I bought a drive enclosure to tear apart, the rest of the stuff I had lying around

One thing I did notice when mentally planning this, was that none of the microusb cables (even my genuine Nokia one that came with a phone) would power the R-Pi properly. Testing between TP1 and TP2 I was lucky to get 4.25v! I ripped the end off of one of them and unsuprisingly, they're made from pretty much a few atoms of metal twisted together. That's a 3mm LED for size comparison. Plan B - ignore the microusb and go for power through GPIO.

The drive enclosure I bought cost about £2.50 delivered. It's the
cheapest one I could find, which presumably was designed by a 5 year old
as they used USB A on the device *sigh*. That "illegal" cable went
straight in the bin. I should have sold it on, see if I could have got
some idiot to try and network 3 computers together with it or something.

I lied before, I did buy one more thing. This useless adapter! I mean really, what purpose does this thing serve? I know, I bought one intentionally, but surely nobody else buys them. It's a HDMI male to female adapter for anybody that didn't guess. Read that again; yep, male to female adapter... as in socket on one side, plug on the other. It makes as much sense to me as the USB A to A cable above. Well anyway, I'm glad they do exist, as I needed one for this.

Cheapo unbranded USB hub. Check out the wonky diodes! I figured it'd be a lot easier deconstructing one with sockets on wires rather than PCB mounted sockets. I was right.

This has to be the most shoddy product I've ever taken apart. It really looks like it was soldered together by some 6 year old kid using a Bic lighter. I'm amazed it works...

I want to keep my R-Pi mod-free for now (waited for years for this one, don't want to destroy it!) - so I left the A plug on the hub, to go straight into the Pi

They "helpfully" labelled the connector on the hard drive enclosure board just in case I wasn't too sure. That board was just glued in to the enclosure. The USB A socket was easy enough to desolder - they hadn't even bothered soldering the casing down, it was just held by the 4 pins.

This made my job easier - I found that the PS2's usb holes were a perfect match for the sockets I salvaged from the hub!

See - exact fit! The thickness of the plastic USB port cover is a perfect spacer to line up with the hole in the case.

Deciding where to put stuff. See what I needed that M-F HDMI adapter for now? I'll dremel a hole for it and glue it in later. Same for the SD card... er... without the glue.

Removing a PCB mounted ethernet jack cleanly was a bit of a pain tbh. Best technique I found was add solder in a big blob covering all 8 pins, then heat the lot and pry it loose. I'm open to suggestions for better methods. I tried solder braid and it just wouldnt remove every spot.

Can you guess what that 8mm thick square of plastic is for? Anyway, 10/100 only needs 2 pairs. Green and Orange.

O/W - 1
O - 2
G/W - 3
G - 6

Well there's one part that works fine!

For the USB (data) cabling I went with 0.25mm Kynar in blue and red (it's all I had).

For power, I used scraps of cable from an ATX PSU. Overkill, but again, best I could find laying around.

Time for a quick test. Here's where things start to go downhill...

Firstly, the bunch of cable you see top left I guess is too thin internally - 4.4 or so between TP1 and 2. I'll deal with that later, so I croc clipped directly on in the mean time.

Everything looked happy enough IRL

But then... sadface.jpg
The Pi didn't like the USB drive. Had I destroyed something? Broken the USB Hub? Hmmm...

For the record, this is currently drawing 0.83A idle. It seemed about right.

I quickly desoldered the USB data lines from the hard disk, and it seemed OK with just the hub.

OK, maybe its the drive controller. After all, it must have cost about $0.05 to manufacture. I soldered one of the original USB sockets back on to try a flash drive in. Plug the drive in, the Pi reboots! Fail again. Got to be a faulty hub, right?

I should add, although the pic doesn't show here, I did try and power the hub though the DC jack in case the R-Pi couldn't handle it on its own - made no difference at all.

I had a spare hub the same as the previous one. Check out the wonky diodes again! They've got a little solder slug trail this time.

What a mess. But still, I tested it in a real PC and it does function properly...

...but not on the Pi. That's with zero hardware mods, just the Pi and the hub with a drive plugged in.

Targus hub from my laptop bag...

...works straight away. Two dodgy hubs, right?

First hub, in a real PC...

...WTF?!

Well, I guess I'll have to buy some more USB hubs and hope the Pi "likes" them.

Just curious, how did you test your usb hubs and what did you solder them too? And what do you use to test power outputs? This is a cool project, I have an empty ps2 slim case too I might try using for something like this.

My suggestion would be to try your hub beforehand (as in, plug it in to the Pi and make sure it works). This was a 1st gen pre-ordered model though; I suspect they've fixed a lot since then. It could have been a software issue as well fo course. Arch linux isn't the most reliable distro

I didn't solder the hub to the pi - that's just plugged in to the USB socket on the board as there was plenty of space to do that.

I don't have one, sorry. It was all done just using stuff I had spare/available at the time. The 6th picture shows it all as far as I remember, although if there's something unclear please let me know.